Genetic architecture of pollination syndrome transition between hummingbird-specialist and generalist species in the genus Rhytidophyllum (Gesneriaceae)
- Published
- Accepted
- Subject Areas
- Biodiversity, Evolutionary Studies, Genetics, Plant Science
- Keywords
- pollination syndrome, geometric morphometrics, QTL, Genotyping by Sequencing, plant mating systems, floral evolution
- Copyright
- © 2015 Alexandre et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Genetic architecture of pollination syndrome transition between hummingbird-specialist and generalist species in the genus Rhytidophyllum (Gesneriaceae) PeerJ PrePrints 3:e861v2 https://doi.org/10.7287/peerj.preprints.861v2
Abstract
Adaptation to pollinators is a key factor of diversification in angiosperms. The Caribbean sister genera Rhytidophyllum and Gesneria present an important diversification of floral characters. Most of their species can be divided in two major pollination syndromes. Large-open flowers with pale colours and great amount of nectar represent the generalist syndrome, while the hummingbird-specialist syndrome corresponds to red tubular flowers with a less important nectar volume. Repeated convergent evolution toward the generalist syndrome in this group suggests that such transitions rely on few genes of moderate to large effect. To test this hypothesis, we built a linkage map and performed a QTL detection for divergent pollination syndrome traits by crossing one specimen of the generalist species Rhytidophyllum auriculatum with one specimen of the hummingbird pollinated R. rupincola. Using geometric morphometrics and univariate traits measurements, we found that floral shape among the second-generation hybrids is correlated with morphological variation observed between generalist and hummingbird-specialist species at the genus level. The QTL analysis showed that colour and nectar volume variation between syndromes involve each one major QTL while floral shape has a more complex genetic basis and rely on few genes of moderate effect. Finally we did not detect any genetic linkage between the QTLs underlying those traits. This genetic independence of traits could have facilitated evolution toward optimal syndromes.
Author Comment
This is the revised version of the manuscript submitted to PeerJ for review.
Supplemental Information
Recombination fraction and LOD scores for each pair of markers
Markers are in the same order as in the linkage map of Figure 4; LOD scores are in the upper triangle and recombination fraction in the lower one. Colours represent a gradient from low LOD score and great recombination fraction (blue) to large LOD scores and small recombination fraction (red).
Profiles of LOD scores for linkage groups with QTLs detected
Abscises are marker position along the linkage group. Red lines are detection threshold corresponding to a type 1 error of 5%, and green rectangles correspond to the 2-LOD confidence region
Information about species used for the PCA performed on the genus
H: hummingbird specialist, G: generalist; (+1) correspond to parental individuals of the hybrid population but were not used to do the PCA